#include<iostream>
using namespace std;
bool f(int m) {
	for (int i = 2; i < m; i++)
		if (m % i == 0)
			return 0;
	return 1;
}
void f1(int str[], int k,int n) {
	for(int i = 0; i < n; i++)
		for(int j = i + 1; j < n;j++)
			if (str[i] < str[j]) {
				int y = str[i];
				str[i] = str[j];
				str[j] = y;
			}
}
int main() {
	int n, k;
	cin >> n >> k;
	int str[10000];
	for (int i = 0; i < n; i++) {
		int x;
		cin >> x;
		str[i] = x;
	}
	f1(str, k, n);
	int m = str[k - 1] - str[n - k];
	if (f(m) == 1)cout << "YES" << endl;
	else cout << "NO" <<endl;
	cout << m << endl;
	return 0;
}